Social and psychological problems associated with addiction to heroin and cocaine have been recognized for many years, but it is only since the appearance of AIDS in 1981 that these forms of drug use have been seriously addressed as a public health issue. The use of heroin and cocaine, especially via injection, is directly responsible for the rapid spread of AIDS in many countries. Further, because the illicit drug trade has generated a huge criminal economy and because drugs are more frequently used to cope with social problems, the drug problem is rapidly becoming a significant agency for social transformation in many countries. The author emphasizes the need to stop characterizing people who use drugs as socially and psychologically marginal and the importance of implementing drug policies based on public health consequencs rather than on criminal prosecution. He recommends that drug control efforts move decisively to implement properly managed methadone maintenance programs and needle and syringe exchange programs. 7 references